BRAF and mucinous adenocarcinoma of the appendix: In tumors of the appendix, the most common BRAF gene mutation is V600E and it is found in less than 5% of cases of sessile serrated lesions without dysplasia [22], low-grade appendiceal mucinous neoplasms [23], appendiceal goblet cell adenocarcinomas [37], well-differentiated neuroendocrine tumors of appendix [37], and mucinous adenocarcinomas of the appendix.